Q1 if v' is frequncy of photon which escapes to ∞ from a star and v is its freuncy when it is emmited from surface of star of radius R then v/v'= ?
Q2Gravitational red shift of phototn escaped to ∞ from starts surface is ?
Q3 For a black hole ,calculate range of GM/c2R
-
UP 0 DOWN 0 1 2
2 Answers
29The Doppler shift
can be expressed as:
Δν vradial
----- = –--------
ν c
The formula given above is valid only when the speed of the source is
small compared to that of light. A more accurate formula for the Doppler
effect which is valid even when the speeds are close to that of light, requires the use of Einstein’s special theory of relativity. The Doppler effect for light is very important in astronomy. It is the basis for the measurements of the radial velocities of distant galaxies.
So i dont think any such question will be asked..as the Doppler equation that is given abv is only valid wen the speed of the particle << speed of light...but photons travel at the speed of light..
106Again last years RTPF
look at the para.. ull be able to solve easily
im just doing the first one:
conserving energy,
hv - GMm/R = hv' (m=rest mass of photon)
